Uterine cancer has long been a dreaded and sometimes fatal form of cancer that can attack women particularly during mid-life. In order to detect such cancer in its early stages and thus enhance the chances of successful treatment, most women periodically undergo a uterine pap smear test. In such tests, a small amount of tissue typically is scraped from the interior walls of the uterus and the uterine cervix and pathologically examined to determine if abnormal or pre-cancerous cells are present. The results of a pap smear test are usually designated as falling into one of three classes with class 1 corresponding to a normal pap smear, class 2 corresponding to the presence of inflamed cells in the uterine tissue and class 3 indicating the discovery of diaplastic or premalignant cells. The great majority of pap smear results fall into classes 1 and 2.
For class 3 pap smears where the presence of some cancer within the uterine tissue is indicated, most gynecologists recommend more extensive tests to determine whether cancer is indeed present and if so its extent and severity. Such tests usually include a surgical procedure known as a uterine cervical conization in which a cone-shaped plug or tissue sample is cut by a surgeon from about the mouth of the cervix and delivered to a pathologist for analysis. The accuracy and reliability of the pathological analysis of the sample and consequently of the gynecologist's ultimate prognosis is highly dependent upon the regularity and symmetry of the particular sample being examined. The ideal sample, for example, is a cleanly cut cone that has a constant cone angle about its circumference and that is symmetric about the central canal of the cervix from which it has been excised.
In the past, the cervical conization procedure has been performed by surgeons using a free hand method wherein a standard surgical scalpel is inserted through the vagina to the uterine cervix and carefully manipulated to excise the sample from about the mouth of the cervix. As can easily be understood, this method of excising the sample has long been plagued with problems and shortcomings and almost always results in an irregular and asymmetric tissue sample that, in turn, leads to less accurate and reliable analytical results. The location of the uterine cervix at the back of the vagina, for example, makes convenient access difficult and the surgeon is usually forced to grasp the scalpel far from the cutting blade such that precise scalpel control becomes difficult. This problem is further exacerbated by the necessity that the surgeon be able to observe the procedure carefully as it is performed to assure the most accurately shaped sample possible. Finally, the quality and particularly the symmetry of the sample has been highly dependent upon the skill and experience of the surgeon largely because the surgeon must simply "eye-ball" or estimate the distance of the cut from the mouth of the cervix and the angle of the scalpel blade with respect to the cervical canal as the procedure progresses. Even the most skilled surgeons have thus found it virtually impossible to extract ideal tissue samples.
A continuing and heretofore unaddressed need exists, therefore, for a new surgical method and enabling instrument for performing a uterine cervical conization that will consistently produce cleanly cut, accurately shaped and highly symmetrical tissue samples for pathological analysis and that can easily be performed with a minimum of prior surgical training and experience. It is to the provision of such a method and apparatus that the present invention is primarily directed.